Isolation of Bacterial RNA from Foods Inoculated with Pathogens.

One strategy bacteria use to acclimate to changing environmental conditions is modulation of gene expression. Alterations in gene expression are indicative of activation or repression of certain physiological responses. In order to understand which genetic responses are utilized to cope with various environmental conditions by analyzing transcriptomes, obtaining RNA of high quality, yield, and integrity is paramount. Here, we describe an acid phenol-chloroform method employed to extract RNA from laboratory grown cell cultures, as well as cultures inoculated onto complex matrices such as lettuce and cold-smoked salmon. The method results in high-quality RNA, which can be used for various downstream processes such as cDNA library construction, RNA sequencing, real-time quantitative PCR, and northern analysis. Extraction of RNA from bacterial foodborne pathogens in conjunction with transcriptome sequencing is a useful technique to elucidate pathogens' transcriptional responses.